The present invention concerns a digital audio equalizer. The conventional equalizer for controlling the amplitude characteristics of a given frequency in an audio signal tends to degrade the sound quality because of the deviation of the characteristics of analog element such as resistance, condenser, etc. Besides, since the characteristics of the analog elements have a given value, it is impossible to adjust the characteristics of each equalizer to the requirements of the user. There is disclosed in U.S. Pat. No. 4,661,982 a digital audio equalizer related to the present invention.